In this study, biologically treated leachate was treated using PAC and PAC + PAM, respectively, to study removal efficiency of COD, SS and color as a function of such influencing factors as pH, dosage of PACand/or PAM. It was found that optimal dosage and pH are 800 mg/L and 6 for PAC. The optimal condition when using PAM + PACfor removal of COD was 10-minute reaction, pH of 5, PAC dosage of 800 mg/L, PAM dosage of 3 mg/L. Effluent quality after coagulation at the optimal conditions met requirements of the tertiary standard described in “Integrated wastewater discharge standard”. Coagulation using PAM + PAC at the optimal condition was recommended for advanced treatment of refractory leachate after biochemical treatment.